Closure or cover apparatus of multiple panels of various types have been proposed and used for the open top of the bed of a pickup truck. Disclosures relating to this general subject matter are found in the following U.S. Pat. Nos. 2,997,330, 3,069,199, 3,858,744, 4,284,303, 4,313,636, 4,418,954, 4,550,945, 4,615,557, 4,695,087, 5,009,457, and 5,011,214.
For the most part, the mounting of panels on the closures of these patents are quite complex in construction and have had limited use as to the way in which the panels can be selectively opened and closed. Moreover, the closures of conventional designs are generally not waterproof, and rain water can penetrate the closures. Thus, goods carried in the truck bed while the closure is in place can often be damaged.
Because of these limitations of conventional multiple panel closures for the open tops of the beds of pickup trucks, a continuing need exists for improvements in such closures. The present invention provides a solution to the complexity problem.
In the use of access doors for electrical equipment cabinets or housings, a relatively large housing requires that the door be generally a single, relatively massive panel. This requires a large amount of space to open the door since the cabinet itself is quite large to be able to house a great amount of electrical equipment therewithin.
Cabinet doors of electrical equipment swing on vertical doors are typically of one-piece construction. As a result, the doors are relatively large and difficult to open and close. A need, therefore, continues to exist for closures for large openings of cabinets for electrical equipment to simplify the way in which the interiors of such cabinets are accessed. The present invention satisfies this need as well.